The invention relates to a boring machine, particularly for woodworking, for boring series of holes and structural bores in plate-shaped workpieces such as cabinet sidewalls, cabinet doors, etc., with a machine frame having a workpiece holder and an adjustable multi-spindle boring assembly arranged over the workpiece holder, a fixed, longitudinally oriented workpiece stop being mounted on the back of the workpiece holder, and which has a stop fixture consisting of stop rails aligned parallel to and projecting laterally at the longitudinal sides of the workpiece holder and whereat adjustable and lockable stop receivers can be introduced into the stop rails, the stop receivers receiving spring-loaded stop platelets, which project at the surface of the workpiece holding fixture, but which can be brought into a pushed back position.
A boring machine of this type is known through DE 33 38 943. In this known boring machine, the stop receivers with the stop platelets are set and locked in the stop rails for the desired boring pattern of the workpiece. The two stop rails are arranged in alignment behind one another and are adjusted in opposite directions by means of adjusting spindles. The operation of the boring machine is quite difficult for a complicated and irregular boring pattern, particularly because the operational so changes as a function of the boring pattern.
It is the object of the invention to provide a boring machine of the type mentioned at the outset, which can be used to incorporate the most varied of multi-row boring patterns of a workpiece into the workpiece with simple operations.
The invention achieves this object in that "n" stop strips with holding fixtures for stop receivers are combined into a stop roller with angles in the cross-section, that the stop roller can be brought into angular positions below the workpiece holder, whereby the stop platelets of the stop rail facing an opening in the workpiece holder project through this opening, and in that the stop roller assumes a defined position with respect to the workpiece holder independently of its angular position in the axial direction.
The stop roller with "n" stop rails permits presetting of "n" rows of hole grids, the adjustment requiring only setting the stop roller in the correct angular position and bringing the multi-spindle boring assembly to the correct spindle and the correct distance from the fixed rear-side stop of the workpiece holder.
In a preferred development, the stop rails have an undercut receiving groove and are combined into a one-piece shape section to reduce component requirements and to simplify the locking of the stop receiver; this is achieved in a simple way in that the stop receivers can be fastened in any position by means of a screw and a nut on the stop roller guided in the receiving groove of the stop rail.
If provision is made in a development for removable mounting of the stop roller in the machine frame, a stop roller with a setting for quite specific bore pattern can be used again and again for such workpieces without further setting procedures. In addition, use can be made of a number of stop rollers, which have a fixed adjustment for different boring patterns.
The adjustment of the stop roller in different angular positions is simplified in that a rotating attachment is assigned to the stop roller, which can be used to turn the stop roller in "n" angle steps in 360 degrees.
For setting the stop receivers with the stop platelets, one advantageous development is characterized in that the edge of the opening facing the forward longitudinal edge of the workpiece holder is designed at the top as a graduated scale or is connected with a graduated scale.
The operation of the boring machine is also facilitated in that the spindles of the multi-spindle boring assembly bear markings that correspond to markings on the stop rails.
The workpiece holder does not impede rotation of the stop roller if the opening in the workpiece holder flares out toward the underside of the workpiece holder, and if the edges of the opening bring the stop platelets into the pushed back position on passing the opening when the stop roller is turned counter to the swiveling direction of the stop platelets.